This project involves the physico-chemical and metabolic characterization of ribosomal RNA and ribosomes of animal cell mitochondria, as well as RNA species (transfer and messenger RNA) with which these elements must interact. Properties of the mitochondrial components will be compared with those of analogous cytoplasmic components, in hopes of furthering our understanding of how mitochondrial biogenesis is coordinated with growth of the cell as a whole, and how disturbance of this coordination might be related to disturbances of growth. For the most part, these studies will employ cultured animal cells.